The information retrieval techniques using the character recognition results from the image are described in JP-A-331006/2000 and JP-A-254622/1998. Whereas, JP-A-23012/2000 describes a translator using a mobile device. In this invention, a line segment for applying the target character line to the graphic user interface (GUI) is displayed on an image display. However, the line segment is fixed in length and position, and it is used only as an index for an operator to capture the image, so that the operator is required to adjust the position and the size of the character line. This prior art reference fails to disclose any character recognition for the image captured by a low resolution image capture device in the mobile device.
JP-A-23012/2000 describes a means, which includes a CCD camera in a mobile telephone or a mobile device to capture an image so as to perform character recognition, and it has a translation function for translating between languages and a retrieval function for retrieving into based on the translation results. However, it does not provide any means for an operator to easily select the target character line out of the image. In contrast, in accordance with the present invention, the character line extraction result from the input image is presented for the operator whenever necessary. This enables easy confirmation of a target character line.
Further, an image capture device to be included in a mobile device or the like is difficult to design to be capable of capturing a high resolution image while balancing the cost and the size. If recognition processing is performed with a low resolution image, the recognition ratio is adversely affected which may inhibit the intended purpose of the operator. Under such circumstances, in accordance with the present invention, the extraction processing of the character line is performed from the captured low resolution image, and then the image of the character line is subjected to an expansion processing. As a result, the resolution of the character line image is enhanced to improve the recognition ratio.